In modern electronic applications, the clock frequencies in particular of digital circuits and the frequencies of analog signals are becoming increasingly higher.
The wavelengths of the processed signals in such cases may reach into the millimeter range and below.
The guidance and distribution of high-frequency signals with wavelengths in the millimeter range normally occur in industrial applications using a conventional printed circuit board technology, in which specific high frequency substrate materials are used which permit a frequency of approximately 100 GHz using adapted microstrip lines.
Patent document US 2013/021118 discusses an exemplary microstrip line.
Such specific high-frequency substrate materials are very expensive, however, and difficult to process. For this reason, generally only one individual layer or one individual coating in the printed circuit board made of this high-frequency substrate material is situated on one side of the printed circuit board stack for distributing the high-frequency signals.
However, the limitation to one individual layer of the printed circuit board stack or one individual signal level for distributing the high-frequency signals restricts the design freedom when designing and routing the high-frequency signal network, since it is not possible to cross different signal lines on one individual layer.